In the Enlightenment, the human body was the new frontier. Lord Byron would become a fitness fanatic obsessed with fat. Surgeons cut into cadavers to discover what had lain concealed before the era’s medical explorations. What a fascination of viscera, architecture and connective goo lay before them!

These early examiners also expected the soul to squirt out of its hiding place. The fact that our eternal essence resists excavation has bedeviled us ever since. Where is the soul amid the body? Must it be that the closer we get to the body’s mysteries, the further we stray from heaven?

This is the central question that Wayne McGregor ponders in “FAR,” the thrilling, perplexing hour-long dance that his London-based company, Random Dance, performed at the Kennedy Center Eisenhower Theater on Thursday.

McGregor tackles a lot here, not always successfully. But “FAR” makes you want to shout your praise for this inquiring, deep-thinking choreographer, for his impossibly fit, masterly dancers, for the fascinating 2003 book that inspired the dance — “Flesh in the Age of Reason,” by Roy Porter — and for “FAR’s” multinational supporters, British, American, French and others, who funded it. If collaboration can be the soul of art, in today’s world, this extraordinary work is a sterling example. But more than that, it is proof that grand, mind-boggling ambition still exists in an environment of cheap, quick and easy.

What unites McGregor and Porter, the late historian and author, is the idea that mind-body-spirit connections were just as intriguing in 1714 as they are in 2014. Today’s interest in neuroscience has its roots in the Age of Reason, when our modern understanding of humanity arose, centered on the capacities of the intellect and the body around it. Religion may have taken a diminished role, but it prompted even more questions.

In McGregor’s hands, this inquisitive atmosphere is rich territory for dance. “FAR” takes its name from the initials in “Flesh in the Age of Reason,” but wisely, McGregor makes few references to concrete history. The most obvious is at the very beginning, when the curtains open on dancers holding torches in the dark. Light was an equal performer here, warming and concealing evocatively throughout, as designed by Lucy Carter, a longtime McGregor collaborator.

Dance audiences are used to seeing extreme flexibility, but there were constant surprises here: fishtail curves in the lumbar spine, an isolated rib cage jutting so far from home that you felt you were looking at a living Picasso of impossible perspectives. A woman stretched her leg high behind her and turned to gaze at the raised foot as if to say: Where the heck did you come from?

Barelegged, in underpants and T-shirts, the dancers were almost inhumanly agile, as if the doctrine of human perfectibility had resulted in android creations with limbs unencumbered by gravity and joints rolling freely under the skin like marbles. Their legs were so striped with muscles and tendons, they looked like stringed instruments.

As beautiful as these humans were, tensions sneaked in — pushing, shoving, shunning. Had we entered a new phase? “FAR” grew murky, a fog of oozy, exaggerated movement. Your thoughts turned to the stamina of the dancers and their amazing memories for steps. After a while, the commissioned score by Ben Frost — echoing chants, quirky vocals, throbbing — felt precious. McGregor was right to stay away from narrative, but this work needed some signposts to help us figure out where the emphasis lay.

Ultimately, and poignantly, McGregor expresses ambivalence towards the body, an ambivalence that is an Enlightenment hangover. As the vessel of our whole self, the corpus just isn’t quite enough, in this view. Once it is exhausted and the dark takes over, a twinkling, starlit dream of transcendence holds sway.

This was McGregor’s masterstroke. Hanging behind the dancers, a computerized pin board studded with LED bulbs had given the space a futuristic feel. But in the last moments, it turned into a field of starlight, and all the ideas that had been raised about bodies and spirits had a glorious place to land.

Sarah Kaufman received the 2010 Pulitzer Prize for Criticism. She is the author of THE ART OF GRACE: On Moving Well Through Life, coming in Nov. 2015. She has been The Washington Post's dance critic since 1996, and after logging time in opera houses, black boxes, and dive bars, what moves her most is seeing grace happen where she least expects it.

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